Did you ASD/Autistic child haVe feeding problems?

My son is 24 months old and only eats Gerber baby food. Eating/chewing is really his only area that he is extremely developmentally delayed in. He has sensory problems and gagging and throwing up. He has caught up pretty well with therapy in most of his other global delays. He has a milk allergy and a soy intolerance, so right now I'm waiting to get Neocate for him, since he refuses Elecare vanilla. I am so frustrated because he hates eating and drinking in general, and won't even finger feed himself anything solid, except for Gerber puffs. He won't even eat pureed table foods. The most he eats is level 3 Gerber dinners and mashed potatoes, and all of the level 2 Gerber meats and fruits. He has been to feeding clinics that say that there is something medically wrong with him and that they cannot work with him until he feels good enough to eat. I agree, and he got an endoscopy and was found to have mild chronic gastritis. He is on Prevacid but still vomits for no reason. I am very worried because I was able to keep his weight up on a Soy pediasure kind of drink called Bright Beginnings which made up for the calories lacking in the baby food, but since he cannot tolerate soy I have to pray he will like one of the Neocate drinks. How can I start making progress with him? His GI doctor is of no help, and they think it's strictly behavioral. I think it may be part of the problem, but he also hasn't been feeling good for so long because of his food intolerances that I think he's afraid to eat and drink. Should I just do with some people say to do and just take away the baby food and make him eat and chew regular food? I'm afraid he would starve first. Please share if you have any experience. Thanks.